Conventionally a green tire is a toroidal assembled but non-cured tire which has been manufactured by assembling on a cylindrical tire cover on a tire building machine. The machine comprises a drum which is supported rotatably on a shaft and the diameter of the building drum can be increased and decreased to allow the tire beads to be held locked or unlocked.
In a known conventional tire building machine there is a slider which is axially reciprocable mounted on the shaft and a plurality of bead locking segments are circumferentially arranged on the outer surface of the slider. The slider and the bead lock segments are operatively connected by a mechanism by which each segment is radially displaced by axial reciprocation of the slider. However, in this type of transmission system, the link mechanism is structurally sturdy when the link is parallel to the pressure acting direction, but structurally weak when the link is skewed to the pressure acting direction.
As a result, the range of stop positions which can successfully be provided for each segment is limited and therefore it is not possible to lock beads with a very wide range of diameters. This limits the flexibility of the machine in relation to different tire sizes.